After the landing, I wanted to check in with Steltzner again to find out what those fateful moments were like for him during the landing.

No mortal member of the press corps gets to be in the control room at NASA's Jet Propulsion Laboratory during a landing. I was crammed into a makeshift press room in another building, watching a video feed from the control room as Curiosity was descending to the surface of Mars. I could see Steltzner on the TV screen, there in the room, but I wanted to know what was going on in his mind.

After the landing, the media all streamed into an auditorium, where NASA would be holding a news conference that he'd be starring in.

I decided to wait outside, hoping to catch him as he came over from the control room. His giddy team was there, but no Steltzner. Eventually he showed up, and high-fived his way through the throng on his way into the auditorium. There was really no time to talk.

It wasn't until later in the week that I could steal him away from his meetings and media interviews for a quick chat over lunch at a nearby — and thankfully empty — restaurant.

On landing night, he said, he was terrified of jumping the gun in declaring that the rover had landed safely.

"I did not want a false positive celebration in the control room under any circumstances," he said.

He told me he'd set up three conditions that had to be met before he would declare success.

"One of our teammates called out 'tango delta nominal,' and that meant that the rover had sent a little postcard with its touchdown velocity, and where it thought it was on the surface of Mars," Steltzner said. "And I had another guy call out 'RIMU stable,' which meant the rover's not moving. And then as soon as RIMU stable was announced, Brian Schratz, who was sitting in the control room with us, was to count to 10 and confirm that the UHF telemetry stream from the rover was continuous. And that meant that the sky crane hadn't fallen back down on top of it."

"UHF is good," Schratz reported.

"He said that ... oh, I remember like, pointing to Al [Chen, JPL engineer], like I'm throwing success into his body. You know, like 'Yes! Let's do it, Al,' " Steltzner said.

Then Chen said it: "Touchdown confirmed. We are safe on Mars."

"And that was incredible," Steltzner said.

Years of planning and worrying had produced total success. Steltzner said he wasn't sleeping well before the landing. I asked if he slept better afterward, and he said yes, but only for a couple nights.

"Now what's interesting — last night I didn't sleep that well, and I sure hope I'm not on to worrying about the next thing and where to go from here."

He's talking about what's next for Adam Steltzner. About what's the next challenge for him. As he told me before the landing, he's a guy who needs something to measure himself against.

"The thing that engineering and physics gave me was, there's a right answer, and I could get to it," he says.

Steltzner told me the next right answer he'd love to get to is a landing system for a mission to Jupiter's watery moon, Europa.

Copyright 2013 NPR. To see more, visit http://www.npr.org/.

Transcript

STEVE INSKEEP, HOST:

It's MORNING EDITION from NPR News. I'm Steve Inskeep.

RENEE MONTAGNE, HOST:

And I'm Renee Montagne.

The Mars rover Curiosity is beginning its fifth day on the red planet. It's been performing flawlessly from the moment it landed. That's been especially gratifying for NASA landing engineer Adam Steltzner.

INSKEEP: Last Friday, while Steltzner was still on pins and needles waiting for the landing to take place, NPR's Joe Palca told us all about Steltzner's decision as a young man to give up rock music and go for a career in space engineering.

MONTAGNE: Today, Joe is checking in with Steltzner again to find out what those fateful moments were like for him during the landing.

JOE PALCA, BYLINE: No mere member of the press corps gets to be in the control room at NASA's Jet Propulsion Laboratory during a landing. I was crammed into a makeshift press room in another building, watching a video feed from the control room as Curiosity was coming in. I could see Adam Steltzner on the TV screen, there in the room, but I wanted to know what was going on in his mind.

After the landing, the media all streamed into an auditorium, where NASA would be holding a news conference that Steltzner would be starring in.

UNIDENTIFIED MAN #1: Where is Adam Steltzner?

UNIDENTIFIED MAN #2: We're waiting.

UNIDENTIFIED MAN #3: Adam.

UNIDENTIFIED MAN #4: Adam (unintelligible).

UNIDENTIFIED MAN #5: Here he comes.

PALCA: Steltzner high-fived his way through the throng and into the auditorium, and there was really no time to talk. It wasn't until later in the week that I could steal him away from his meetings and media interviews for a quick chat over lunch at a nearby - and thankfully empty - restaurant. He said on landing night, he was terrified of jumping the gun in declaring that the rover had landed safely.

ADAM STELTZNER: I did not want a false positive celebration in the control room under any circumstances.

PALCA: Steltzner told me he'd set up three conditions that had to be met before he would declare success.

STELTZNER: One of our teammates called out tango delta nominal.

UNIDENTIFIED WOMAN: Tango delta nominal.

STELTZNER: And that meant that the rover had sent a little postcard with its touchdown velocity and where it thought it was on the surface of Mars. And I had another guy who called out RIMU stable.

UNIDENTIFIED MAN #6: RIMU stable.

STELTZNER: Which meant the rover's not moving. And then, as soon as RIMU stable was announced, Brian Schratz, who was sitting in the control room with us, was to count to 10 and confirm that the UHF telemetry stream from the rover was continuous. And that meant that the sky crane hadn't fallen back down on top of us.

BRIAN SCHRATZ: UHF is good.

STELTZNER: He said that - oh, I remember, like, pointing to Al like I'm throwing success into his body. You know, like, yes. That - do it, Al.

AL CHEN: Touchdown confirmed. We're safe on Mars.

(SOUNDBITE OF CHEERING)

STELTZNER: And it was - that was incredible.

PALCA: Years of planning and worrying had produced total success. Steltzner had told me he wasn't sleeping well before the landing. I asked if he slept better afterwards, and he said, yes, but only for a couple nights.

STELTZNER: You know, what's interesting is last night I didn't sleep that well, and I sure hope that I'm not on to worrying about what's the next thing and where to go from here.

PALCA: He's talking about what's next for Adam Steltzner. What's the next challenge for him? As he told me a few weeks ago, he's a guy that needs something to measure himself against.

STELTZNER: The thing that engineering and physics gave me was this idea that there was a right answer, and I could get to it.

PALCA: I asked Steltzner what the next right answer he'd love to get to might be, and he said designing a landing system for a mission to Jupiter's watery moon, Europa.

Joe Palca, NPR News.

MONTAGNE: We first met Adam Steltzner as part of a project about people who make discoveries and invent new things, a project we're calling Joe's Big Idea. Transcript provided by NPR, Copyright NPR.